package com.supergzt.utils;

import com.supergzt.constant.StringConstants;
import org.springframework.util.LinkedCaseInsensitiveMap;
import org.springframework.util.StringUtils;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Map;

/**
 * 客户端工具类
 *
 * @author ruoyi
 */
public class ServletUtils {
	/**
	 * 获取String参数
	 */
	public static String getParameter(String name) {
		return getRequest().getParameter(name);
	}

	/**
	 * 获取String参数
	 */
	public static String getParameter(String name, String defaultValue) {
		return getRequest().getParameter(name) == null ? defaultValue : getRequest().getParameter(name);
	}

	/**
	 * 获取Integer参数
	 */
	public static Integer getParameterToInt(String name) {
		return Integer.parseInt(getRequest().getParameter(name));
	}

	/**
	 * 获取Integer参数
	 */
	public static Integer getParameterToInt(String name, Integer defaultValue) {
		return getRequest().getParameter(name) == null ? defaultValue :Integer.parseInt(getRequest().getParameter(name));
	}

	/**
	 * 获取request
	 */
	public static HttpServletRequest getRequest() {
		try {
			return getRequestAttributes().getRequest();
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * 获取response
	 */
	public static HttpServletResponse getResponse() {
		try {
			return getRequestAttributes().getResponse();
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * 获取session
	 */
	public static HttpSession getSession() {
		return getRequest().getSession();
	}

	public static ServletRequestAttributes getRequestAttributes() {
		try {
			RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
			return (ServletRequestAttributes) attributes;
		} catch (Exception e) {
			return null;
		}
	}

	public static String getHeader(HttpServletRequest request, String name) {
		String value = request.getHeader(name);
		if (StringUtils.isEmpty(value)) {
			return StringConstants.NULL;
		}
		return value;
	}

	public static Map<String, String> getHeaders(HttpServletRequest request) {
		Map<String, String> map = new LinkedCaseInsensitiveMap<>();
		Enumeration<String> enumeration = request.getHeaderNames();
		if (enumeration != null) {
			while (enumeration.hasMoreElements()) {
				String key = enumeration.nextElement();
				String value = request.getHeader(key);
				map.put(key, value);
			}
		}
		return map;
	}

	/**
	 * 将字符串渲染到客户端
	 *
	 * @param response 渲染对象
	 * @param string   待渲染的字符串
	 */
	public static void renderString(HttpServletResponse response, String string) {
		try {
			response.setStatus(200);
			response.setContentType("application/json");
			response.setCharacterEncoding("utf-8");
			response.getWriter().print(string);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}
